Image processing apparatus and image processing method

Abstract

Provided is an image processing apparatus including an enhancement layer prediction section configured to generate a predicted image of a first prediction block of a color difference component in an enhancement layer of an image subjected to scalable video decoding using a prediction function of a luminance based color difference prediction mode having coefficients calculated from a luminance component and the color difference component in a position corresponding to the first prediction block in a base layer.

1 . An image processing apparatus comprising:
 an enhancement layer prediction section configured to generate a predicted image of a first prediction block of a color difference component in an enhancement layer of an image subjected to scalable video decoding using a prediction function of a luminance based color difference prediction mode having coefficients calculated from a luminance component and the color difference component in a position corresponding to the first prediction block in a base layer.   
     
     
         2 . The image processing apparatus according to  claim 1 , wherein, when a prediction mode other than the luminance based color difference prediction mode is specified for a second prediction block in the base layer corresponding to the first prediction block, the enhancement layer prediction section generates the predicted image of the second prediction block using the prediction function having the coefficients when separate prediction mode information acquired for the first prediction block indicates the luminance based color difference prediction mode. 
     
     
         3 . The image processing apparatus according to  claim 1 , further comprising:
 a base layer decoding section configured to decode an encoded stream of the base layer according to a first encoding scheme that does not support the luminance based color difference prediction mode; and   an enhancement layer decoding section configured to decode the encoded stream of the enhancement layer according to a second encoding scheme that supports the luminance based color difference prediction mode.   
     
     
         4 . The image processing apparatus according to  claim 1 , wherein, when the luminance based color difference prediction mode is specified for a second prediction block in the base layer corresponding to the first prediction block, the enhancement layer prediction section generates the predicted image of the second prediction block using the prediction function having the coefficients. 
     
     
         5 . The image processing apparatus according to  claim 1 , wherein the enhancement layer prediction section calculates the coefficients by substituting only a portion of the luminance component and the color difference component in a position corresponding to the first prediction block in the base layer into coefficient calculation formula of the luminance based color difference prediction mode. 
     
     
         6 . The image processing apparatus according to  claim 1 , further comprising:
 a memory configured to store pixel values of the luminance component and the color difference component in the base layer before a deblocking filter being applied,   wherein the enhancement layer prediction section calculates the coefficients using the pixel values stored in the memory.   
     
     
         7 . An image processing method comprising:
 generating a predicted image of a first prediction block of a color difference component in an enhancement layer of an image subjected to scalable video decoding using a prediction function of a luminance based color difference prediction mode having coefficients calculated from a luminance component and the color difference component in a position corresponding to the first prediction block in a base layer.   
     
     
         8 . An image processing apparatus comprising:
 an enhancement layer prediction section configured to generate a predicted image of a first prediction block of a color difference component in an enhancement layer of an image subjected to scalable video coding using a prediction function of a luminance based color difference prediction mode having coefficients calculated from a luminance component and the color difference component in a position corresponding to the first prediction block in a base layer.   
     
     
         9 . The image processing apparatus according to  claim 8 , wherein the enhancement layer prediction section selects, regardless of whether a luminance based color difference prediction mode is selected as an optimum prediction mode for a second prediction block in the base layer corresponding to the first prediction block, the optimum prediction mode for the second prediction block from one or more prediction modes including the luminance based color difference prediction mode using the prediction function having the coefficients. 
     
     
         10 . The image processing apparatus according to  claim 8 , further comprising:
 a base layer encoding section configured to encode an encoded stream of the base layer according to a first encoding scheme that does not support the luminance based color difference prediction mode; and   an enhancement layer encoding section configured to encode the encoded stream of the enhancement layer according to a second encoding scheme that supports the luminance based color difference prediction mode.   
     
     
         11 . The image processing apparatus according to  claim 8 , wherein the enhancement layer prediction section selects, when a luminance based color difference prediction mode is selected as an optimum prediction mode for a second prediction block in the base layer corresponding to the first prediction block, the luminance based color difference prediction mode using the prediction function having the coefficients as the optimum prediction mode for the second prediction block. 
     
     
         12 . The image processing apparatus according to  claim 8 , wherein the enhancement layer prediction section calculates the coefficients by substituting only a portion of the luminance component and the color difference component in a position corresponding to the first prediction block in the base layer into coefficient calculation formula of the luminance based color difference prediction mode. 
     
     
         13 . The image processing apparatus according to  claim 8 , further comprising:
 a memory configured to store pixel values of the luminance component and the color difference component before a filter being applied,   wherein the enhancement layer prediction section calculates the coefficients using the pixel values stored in the memory.   
     
     
         14 . An image processing method comprising:
 generating a predicted image of a first prediction block of a color difference component in an enhancement layer of an image subjected to scalable video coding using a prediction function of a luminance based color difference prediction mode having coefficients calculated from a luminance component and the color difference component in a position corresponding to the first prediction block in a base layer.